Questions about Transporation/lodging

I had intentions on buying just Sunday tickets, not just for RATM but also a handful of other bands I really like that are playing on Sunday, seemed like a cheap way to attend Coachella. Anyways I bought two 3-day passes and was wondering where is the best place to fly in at, a friend told me San Diego but the problem is both me and my gf are only 20 so we couldn't rent a car. Is there reliable transportation options from SD to Indio? Or perhaps if we were to stay in Palm Springs area is there a way to get to the concert back and forth like a bus or shuttle of some sort.

Also what is the best place to stay, in terms of price and most bang for your buck. Thanks for any help you can give.